Tube handling apparatuses are mentioned in patents from the 60s and differ in certain aspects but in general all maintain the same basic configuration. Among the numerous documents in this field, we can mention the following background art: AR037630 A1; U.S. Pat. Nos. 3,315,822; 4,236,861; 4,371,302; 4,474,520; 4,486,137; 4,822,230; 5,127,790; 5,451,129; 5,458,454; US 2003-0147726; U.S. Pat. Nos. 6,705,414; 6,860,694; 7,021,880; WO 2004-092533 A1; US 2007-0031215; U.S. Pat. No. 7,431,550; US 2008-0253866; US 2008-0263990; US 2009-0056932; U.S. Pat. Nos. 7,552,775 and 7,568,533.
They are all formed by a catwalk or main structure located in front of the work table of the equipment and mediated by an inclined plane that may or not be an integral part of the tubular pipe handling apparatus. At the sides of this structure perpendicularly to the longitudinal axis of the same there are arranged racks used to accumulate the tubes removed from the well or vice versa. This basic arrangement does not differ from equipments hereinafter named “conventional” wherein tubes are handled from the catwalk by wires attached to them and conducted by means of hoists or winches from the work table.
The introduction of aids when lifting pipes began with a simple push skid in a trough located on the catwalk that facilitated push from or toward the inclined plane positioning the pipe at the end of the work table of the equipment.
Patents as U.S. Pat. No. 3,143,221 to Blackmon mention this kind of skid used that ends up being incorporated into all subsequent versions of the pipe handling apparatus. Even today many apparatuses still use this simple push configuration, which does not cover all the expectations as it is not able to place the tube close enough to the wellhead, frequently located a long distance from the end of the work table. Moreover, the angle of the inclined plane does not helps also to the proper disposition of the tube as a longer travel of the skid would make the end of the tube override the operator, making him difficult to couple the tube to the elevator of the service equipment rig (hereinafter so called for drilling, work over, pulling, mining or similar equipment).
This difficulty was later solved by including an additional tray that could move with the tube placed on a trough included in the same, which in turn was arranged within a cavity in the main structure or catwalk. This trough allowed the vertical movement and tilting to facilitate placement of the tube proximate end at a height about the hips of the operator and approximately 50 cm away from the wellhead center. Several patents illustrate this configuration with various degrees of both constructive and operational complexity.
The present description in the U.S. Pat. No. 3,169,645 to Freeman shows a primitive design wherein the entire top surface is lifted by a plurality of hydraulic cylinders. This configuration is very limited as to the lifting capacity and cannot cover apparatuses with high work tables (hereinafter called substructures). Later inventions such as U.S. Pat. No. 3,792,783 to Brown evolved to allow lifting only one side of the tray tilting the end near the substructure. This same kind of configuration can be found in most modern patents as U.S. Pat. No. 7,568,533 to Felt. The problem of these configurations lies in limiting the height of the substructure. While the angle of attack of the tubes from the work floor is obviously better than with an inclined plane, it is not possible yet to bring the end of the pipe closer to the wellhead center without achieving great reach heights for the operator in substructures of large dimensions.
The development and improvement of tilting and lifting of trays were obtained through the incorporation of arms and joints that not only allow an inclination and elevation but also a horizontal shift to the wellhead center, improving the approach but additionally complicating construction and operation. These solutions can be found in U.S. Pat. No. 4,380,297 to Frias and U.S. Pat. No. 4,386,883 to Hogan, the latter sets trends in this kind of tray with articulated arms used in current models. These arms allow additional flexibility when positioning and approaching the transport tray to the substructure. This kind of arms are disclosed in patents such as U.S. Pat. No. 4,494,899 to Hoang, U.S. Pat. No. 6,079,925 to Morgan and more modern patents such as U.S. Pat. No. 6,877,942 to Eastcott, U.S. Pat. No. 6,899,510 to Morelli, or U.S. Pat. No. 7,163,367 to Handley.
While strongly improving the approach and flexibility in different substructures, the problem is that the inclined plane is not a completely disposable item and should be used for other maneuvers such as lifting of additional components (bits, Top-Drives (top drive systems, such as a hydraulic or electric engine suspended from the mast of a drilling platform, which rotates the drill, the string and a drilling bit and used in the drilling process), etc.) without using complex cranes or other lifting equipment. Moreover, in case of failure of the tube lifting equipment, the operation should still be possible by means of conventional methods. In this way the pipe handling apparatus should be able to be adapted to inclined planes existing in the service equipment, or should include an inclined plane to adapt to any service equipment in a flexible manner. Moreover, another problem of including arms and hinges is the rigidity loss of the system, that is more evident when lifting in high substructures (above 6 meters) and large tubular elements such as collars or “heavy-weights” (heavy drill rods; thick wall exploration tubes used in the bottom of a drilling string), that can exceed 3 metric tons. These systems operate under full load as an inverted pendulum, being inherently unstable, and making large swinging movements that affect the life and structural capacity of the equipment. This behavior is increased in systems like those found in U.S. Pat. Nos. 4,386,883 or 4,494,899 with the tray articulated rear arm (distal side of the substructure).
A different solution can be found in U.S. Pat. No. 4,403,898 to Thompson wherein the carrier tube tray slides directly on an inclined plane included in the pipe handling apparatus. This inclined plane has an element to push the tray along a guide included in the same, displacing it to the work table. Once at the highest position the tray has another tray incorporated to extend its length and bring the end of the pipe closer to the wellhead center. It is important to note that at the same time one arm in the distal part of the tray can raise this end to reduce the angle thereof relative to the substructure. Other variants of the same kind of solution can be found in U.S. Pat. No. 7,404,697 to Thompson, US application 2009/0053013 to Maltby and U.S. Pat. No. 7,832,974 to Fikoswki. Another similar solution but with the tray included in the inclined plane can be found in US application US 2010/0068006 to Littlewood, wherein the initial movement of the tube is produced by a simple push carriage so that once the tube is located in the tray, the tray is rotated on the top of the inclined plane, advancing it and then the tube is pushed forward. All these solutions suffer from the problem of motion complexity, which must be coordinated by a PLC system (acronym of “Programmable Logic Controller”) to prevent non programmed movements to happen in order to avoid collisions between components. This adds complexity, cost and maintenance requirements to the apparatus, and involves training the operators to use the same. On the other hand, one of the design problems found in the equipments with embedded inclined plane is the elevation of the same (rig up), as it must start from the horizontal position to then attain a rotation angle of up to 150°. This movement is hampered by the weight of the plane itself that is greater than that of a conventional plane due to the addition of pipe handling driving and motion systems.
Alignment is one of the critical factors on articulated equipments, as it should always correctly be aligned with the wellhead center. This is complex to be achieved during assembly (rig up) of the equipment as references are not accurate. On the other hand, the operational motion and the aforementioned pendulum effect cause significant loads on the ground that may sink causing changes in the alignment defaults. This is evident during heavy rain or soft grounds that cause inevitable positioning changes. This factor is not as incident with inclined plane including equipment, since once aligned they are inherently less susceptible to changes. It is important to note that on articulated equipment, any change of position to the floor height is amplified by the distance of the arms, and that this is not the case with apparatuses with inclined plane.
None of the previous inventions provide a mechanism to raise the tubular pipe handling apparatus for transportation autonomously from the ground level to the height of the transportation means. This is of vital importance because otherwise cranes must be available in order to place the equipment on trailers for transportation. Conventionally trucks with hoists or winches called “oil trucks” are used, but they lack of ductility as the great length of this tube handling apparatuses complicates handling and placement on trailers.
In all the patents found, the derailment means of the trays used to remove sideways the tubes are operated remotely but are an inner integral part of the tray, and should have some sort of logic to not be triggered accidentally during the raising or lowering of tubes from or toward the wellhead. This complicates the system and operation by the operators.
The common method of construction of apparatuses is through welded tubular latticed structures. These structures end up being very rigid and susceptible to the appearance of cracks and breakage during operation.
Therefore, it is necessary to design an improved, height adjustable, portable tubular pipe handling apparatus as well as the corresponding operation methods, as defined in the present invention.